topic Re: MPC5744P Chip Version in Model-Based Design Toolbox (MBDT)

MPC5744P Chip Version

260068845 — Wed, 15 May 2019 11:09:45 GMT

Hello,

I have a problem. When using the cycle execution code, the 2016 version of the MPC5744P chip can only perform a 50Hz cycle. If the cycle is higher than this cycle, it will not run. The same model can execute the 200Hz cycle in the 2018 version of the MPC5744P. I would like to ask if there are different places in the next two versions of the chip, thank you?

Re: MPC5744P Chip Version

constantinrazva — Thu, 16 May 2019 15:19:08 GMT

Hello 260068845@qq.com‌,

Can you attach your model?

Kind regards,

Razvan.

Re: MPC5744P Chip Version

260068845 — Thu, 16 May 2019 15:48:57 GMT

Hello constantinrazvan.chivu,
Due to the confidentiality of the project, the code was modified and the actual code was many times larger than this project. I wonder if the amount of code has an impact?Thanks！！！

Re: MPC5744P Chip Version

constantinrazva — Tue, 21 May 2019 14:21:50 GMT

Hello 260068845@qq.com‌,

Could you clarify what do you mean by

the 2016 version of the MPC5744P chip

and

2018 version of the MPC5744P.

Could you specify what revision (Rev Xn with SCH Rev A/B/etc) you are referring to?

Kind regards,

Razvan.

Re: MPC5744P Chip Version

constantinrazva — Tue, 21 May 2019 14:25:58 GMT

And 260068845@qq.com‌, to answer your question here

Huang Zewu wrote:
Hello Constantin Razvan Chivu,
Due to the confidentiality of the project, the code was modified and the actual code was many times larger than this project. I wonder if the amount of code has an impact?Thanks！！！

Yes, the amount of code can impact the application. The way we run the application is the following:

we get the fixed discrete step from the Simulink model (this is user-configurable)
we then configure a timer to trigger the step function (main loop of the application) at the specified time

So if you configure a very low fixed step and have a big application, it will not work as expected (e.g.: if you have code in the main loop that requires X us, and you've set the fixed step to something less than X us). But other than that, it shouldn't impact the application. Can you profile the code from the main loop and see if it's greater than the fixed step you've set in your model?

Kind regards,

Razvan.

Re: MPC5744P Chip Version

constantinrazva — Tue, 21 May 2019 14:30:48 GMT

Another thing I'd like to mention is that you can use a PIT block (that you can find in Core and System Blocks -> PIT Timer) to trigger a subsystem you want. This way, you can make a simple scheduler, not depending only on the timer that drives the main loop. The function call generator block you use runs a software timer - so it uses CPU to increment values, counting time. If you were to use the PIT block, the CPU would be freed; the counting part being done in the LPIT hardware.

Hope this helps,
Razvan.